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32 Cards in this Set
- Front
- Back
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What has no synaptic delay?
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Electrical synapses (gap junctions)
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What type of synapse allows for complex integration? and why?
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Chemical synapses b/c of diversity
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What are the two main types of chemical synapse receptors?
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Ionotropic
Metabotropic |
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What do ionotropic postsynaptic receptors do?
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Directly gate ion channels
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Describe the synaptic delay for ionotropic receptors.
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Minimal synaptic delay
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What to metabotropic receptors do?
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Indirectly gate ion channels via G protein
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Describe the synaptic delay for metabotropic receptors.
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Longer synaptic delay.
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T/F - The diversity of effects in chemical synapses is due to the types of ligands.
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False - it is due to types of receptors
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What is unique about Glu (NMDA)
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Only NT that is ligand sensitive and voltage sensitive.
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Where are muscarinic ACh receptors found?
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On sympathetic ganglia cells.
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In a sympathetic ganglion cell, stimulating a presynaptic cell to generate an AP, releasing ACh will result in what at the postsynaptic end?
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2 potentials
(1 fast, and 1 slow) |
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In a postsynaptic sympathetic ganglion cell, the fast ESPS is associated with what receptor?
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ACh binds to nAChR (nicotinic acetylcholine receptor).
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In a postsynaptic sympathetic ganglion cell, the slow ESPS is associated with what receptor?
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ACh binds to mAChR (muscarinic acetylcholine receptor)
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In a postsynaptic sympathetic ganglion cell, the binding of ACh to nAChR does what? Final result potential?
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Opens ion channel.
Fast, direct increased EPSP. |
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In a postsynaptic sympathetic ganglion cell, the binding of ACh to mAChR does what? Final result potential?
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Closes M-type K+ channel via G-protein (may include 2nd messenger)
Slow, indirect decreased conductance EPSP. |
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In the CNS, is a PSP by itself effective?
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No
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In the CNS, PSP's are generated where and what happens while they propagate.
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In the trigger zone (axon hillock/initial segment).
Propagate decrementally. |
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Synaptic efficacy depends on what? x3
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1. Passive properties
2. Spatial summation 3. Temporal summation |
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What needs to happen for IPSP to "shunt" EPSP's?
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IPSP must be near the trigger zone.
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Describe how shunting occurs.
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An excitatory synapse will propagate EPSP decrementally along dendrite.
When EPSP reaches cell body, they will encounter IPSP (anion influx), which will knock off (shunt) cations. Net effect, is that less positive ions will reach the trigger zone, decreasing the potential. |
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Presynaptic inhibition and facilitation is mediated by what synapse?
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Axo-axonic synapses
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What is required for induction of LTP (long term potentiation) in the hippocampus?
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NMDA-type receptors
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Excitation of what will unblock NMDA receptors?
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Significant depolarization of AMPA receptor
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NMDA receptors are blocked by what during resting membrane potential?
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Mg2+
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In LTP, increased Ca2+ activates what?
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CaMKII (Ca2+/Calmodulin dependent Protien Kinase II)
and PKC (Protein Kinase C) |
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In LTP, Ca2+ initiated kinase activation result in what?
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Insertion/stabilization of AMPA receptors.
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During development, what occurs at "previously silent" synapses?
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AMPA insertion/stabilization.
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Ca2+ influx may trigger release of what "retrograde messenger?"
What is immediate result? What is net result? |
Nitric Oxide
Enhanced Glutamate release Enhanced Pre- and Post-synaptic function. |
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Why is the hippocampus susceptible to stroke?
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Due to its "watershed location."
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What is the primary blood supply of the hippocampus?
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Anterior Choroidal Artery
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Ischemia in the hippocampus increases what? and why?
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Synaptic glutamate increase (causing positive feedback) thus neurons fire themselves to death.
B/c reuptake of Glu is impeded by astrocytes which are O2 dependent. |
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Impaired memory occurs when excessive excitation results in death of which cells?
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Pyramidal cells in the CA1 region of the hippocampus
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